Из заданного слова получить другие слова

Option Explicit
Dim S As String, S2 As String, T As String, t1 As String
Dim N As Long, i As Long, k As Long
 
Private Sub cmdD_Click()
    txt2.Text = ""
    k = 0
    cmdD.BackColor = vbRed
    cmdD.Refresh
    Open "ИИ.txt" For Input As #1
    S = txtT.Text
    S2 = S
    Do
        Line Input #1, T
        If T = "" Then GoTo 100
        S = S2
        
        For i = 1 To Len(T)
            t1 = Mid$(T, i, 1)
            N = InStr(S, t1)
            
            If N Then
                Mid$(S, N, 1) = "="
            ElseIf t1 = "й" Then
                N = InStr(S, "и")
                If N Then Mid$(S, N, 1) = "=" Else GoTo 100
            ElseIf t1 = "и" Then
                N = InStr(S, "й")
                If N Then Mid$(S, N, 1) = "=" Else GoTo 100
            ElseIf t1 = "ё" Then
                N = InStr(S, "е")
                If N Then Mid$(S, N, 1) = "=" Else GoTo 100
            ElseIf t1 = "е" Then
                N = InStr(S, "ё")
                If N Then Mid$(S, N, 1) = "=" Else GoTo 100
            Else
                GoTo 100
            End If
        Next
        
        If k Then txt2.Text = txt2.Text + vbCrLf
        k = k + 1
        txt2.Text = txt2.Text + Str$(k) + ". " + T
100
    Loop Until EOF(1)
    cmdD.BackColor = vbGreen
    Close #1
End Sub